The present invention relates to a diffuser set for chilled drinks dispensers fitted with "post-mix" valves.
In the technical field pertaining to the delivery and distribution of chilled drinks, the use is known in the prior art of drinks dispensers wherein the drink is prepared immediately before being delivered through the mixing of two or more components which, appropriately chilled, are separately taken to the mixing point. More specifically, the dispensers comprise delivery groups which are individually provided with two distinct ducts that feed the post-mix valve and that, in turn, receive the components of the drink from related distinct supply lines. One of these ducts conveys the syrup, whereas the other one conveys either carbonated water (the so-called soda) or flat water, i.e. water that is free of added gases. The soda, mixing with the syrup, dilutes it allowing to prepare a carbonated drink, whereas the flat water allows to prepare a non carbonated drink such as tea.
Each diffuser set also comprises a communication duct allowing for its collective connection together with other similar diffuser sets to the same supply line in order to allow to obtain dispensers fitted with multiple delivery taps.
In the preparation and in the delivery of the chilled drinks, a general problem is represented by the need to maintain the delivery temperature of the drink constantly controlled.
This is obtained by means of refrigerating systems comprising a tank containing a cooling fluid. In the tank are immersed cooling coils through which the components of the drinks are made to flow; after being chilled, the components are conveyed to the aforesaid dispensers along a section of the supply line positioned between the tank and the dispenser itself.
Along this section of line, however, the components of the drink tend to absorb heat from outside and to become warmer. This disadvantageous effect is particularly intensified by delivery stops because if the distribution system remains idle for some time, the carbonated or flat water located in the aforesaid sections of the respective supply lines tends to warm up more easily.
To obviate this, solutions have been sought that entail the creation of a continuous recirculation of a flow of a component of the drink to be mixed with the syrup, for instance soda, which through a particular pump is continuously made to circulate from the chilling tank to the dispenser and vice versa. One possible way to realize this concept can be obtained with the aid of the same diffuser sets provided for "post-mix" valves. Therein, a flow of carbonated or flat water is made continuously to transit through the duct joining the various diffuser sets of the same dispenser, chilling them even during stops in the delivery of the drinks.
The sets thus obtained require, however, rather costly and cumbersome pumps and thus only one unit is provided for each chilling tank regardless of the number of coils contained, or in other words, regardless of the number of different components of the drink which are conveyed to the dispenser.
Under such conditions, diffuser sets known in the prior art, having available only one duct for the possible continuous recirculation of the chilled soda or of the chilled flat water, in practice do not allow to obtain chilled drink dispensers able to deliver heterogeneous drinks, meaning by that the ability to deliver carbonated drinks through a certain group of delivery taps and flat drinks through other groups of taps.
Moreover, diffuser sets known in the prior art, although used to obtain dispensers able to deliver exclusively drinks of a single type, all carbonated or all flat, do not allow to eliminate the recirculation of at least one of the components of the drink. At least one of the diffuser sets, if not all, must provide for the possibility of recirculating a component of the drink towards the chilling tank, if the risk of delivering drinks at less than optimal temperatures is to be avoided, at least for a certain time interval after a stop in the distribution system.